The above fan case for covering the fan blades of an aircraft jet engine is required to be lightweight and have high strength, and in order to meet these requirements, there are attempts of adopting a composite material consisting of reinforcing fibers and a thermosetting resin as the raw material of the fan case.
The above fan case has an annular outward flange, which is typically coupled with an engine nacelle, integrally formed at one end of a case main body covering the fan blades. Therefore, when a composite material consisting of reinforcing fibers such as carbon fibers and a thermosetting resin such as an epoxy resin is used as the raw material, both the case main body and the annular flange have a plurality of fabric layers including a fabric composed of reinforcing fibers such as carbon fibers.
To manufacture the above fan case (cylindrical case) using a composite material consisting of reinforcing fibers and a thermosetting resin, a cylindrical mandrel is rotated on its axis while the fabric is wound around the molding surface of the mandrel to form a laminate of fabric layers, and this laminate is heated to cure the thermosetting resin with which the laminate is pre-impregnated.
In the above fan case, in order to secure sufficient strength and rigidity, it is necessary that reinforcing fibers having an inclination angle of ±0-75° to the circumferential direction of the case main body are included between the plurality of fabric layers, and such a fan case is described in Patent Document 1, for example.